Physical Conditioning and Wheelchair Propulsion

Physical capacity is important to the development of wheelchair propulsion performance. Five articles have explored the relationship between physical conditioning and capacity, and wheelchair propulsion.

Discussion

Kilkens et al. (2005) investigated the longitudinal changes in manual wheelchair skill performance and parameters for physical capacity of people with SCI at the beginning of their inpatient rehabilitation, at three months and at point of discharge. The wheelchair circuit consisted of eight standardized tasks in a fixed sequence on a treadmill, hard and soft surface. The physical capacity parameters included upper extremity muscle strength, peak oxygen uptake and peak power output (PO peak). Their study found a significant relationship between upper extremity strength and PO peak as parameters of physical capacity that influence wheelchair propulsion performance during inpatient rehabilitation of individuals with SCI.

Dallmeijer et al. (2005) tracked 132 participants across eight SCI rehabilitation centres to describe the changes that occurred in relation to wheelchair propulsion capacity (WPC) from the start of rehabilitation, three months post and at discharge. An overall improvement of 45% in WPC, as measured by Maximum Power Output (POmax) was found over the full course of rehabilitation, with significantly higher POmax being noted for participants with incomplete lesions, participants who were younger, and participants who were male. The authors suggest that these findings can help guide clinical intervention related to WPC, individualizing intervention based on these characteristics. However, the course of intervention related to WPC during rehabilitation was not described; it is unclear if there was a standard approach to intervention.

deGroot et al. (2007) examined mechanical efficiency (ME) of wheelchair propulsion, of people with SCI at the start of their rehabilitation, three months post, at discharge and one year post discharge. They are hypothesizing that higher mechanical efficiency, which they attributed to an improved propulsion technique, would show higher peak power outputs (POpeak), better performance times and lower percentage heart rate reserve (%HHR). They found that ME was significantly related to wheelchair propulsion capacity as measured by POpeak, and to the performance time of two wheelchair performance tasks, during rehabilitation and one year post discharge. The authors attributed the higher ME indirectly to propulsion technique, but no data was presented related to participants’ propulsion technique.

Rodgers et al. (2001) hypothesized that a program which combines stretching and strengthening of the muscles critical to propulsion as well as aerobic training would result in more efficient wheelchair propulsion. The supervised training program was completed three times per week for six weeks. Pre and post testing found the only significant wheelchair kinetic change was the propulsive moment, which represented a 14% improvement. The authors suggest that this finding in conjunction with the lack of change noted in the hand rim peak forces and a significant decrease in stroke frequency indicate biomechanical efficiency was improved without increasing stresses on the upper extremity joints. The authors suggest that the findings of significant increases in three kinematic measures (shoulder flexion/extension, maximum elbow extension and trunk flexion) can augment propulsion, especially at times of fatigue.

Qi et al. (2015) explored the relationship between perceived rate of exertion and physical capacity during typical mobility activities. Eleven people with a spinal cord injury level lower than T6 completed propulsion testing on a treadmill in their own wheelchairs, at three specified rates of speed which the authors equated to three different mobility activities; a self-selected comfortable speed at 1ms equated to the minimal safe speed to cross a street with traffic lights, 1.3 ms equated to typical able bodied walking speed, and 1.6ms equated to the upper limit of a self-selected speed. A final test of propulsion was completed using the first test speed with increasing resistance until exhaustion. The authors found that most participants chose a propulsion speed of 1.1 ms as a comfortable speed, which corresponded to approximately 53% VO2peak and an average heart rate of 104 beats per minute (0.69% HRmax). They also found that there were no significant differences between the rate of perceived exertion for respiration and arm. The authors indicate these findings suggest that self-selected propulsion speeds of low and moderate rates, which correspond to typical daily life mobility activities, can provide cardiovascular conditioning.